JPH08223073A - Dual band radio communication equipment - Google Patents

Abstract

PURPOSE: To provide a heterodyne dual band radio communication equipment which is used in common in two bands like 800MHz band and 1.5GHz band of a digital land mobile radiotelephone. CONSTITUTION: A reception intermediate frequency fIFR is made equal to a transmission/reception frequency difference ΔTR1 or ΔTR2 between first and second radio frequency bands, and a frequency fIFT is set to two-fold frequency 2ΔTR1 or 2ΔTR2 of the transmission/reception frequency difference, and a first local oscillation signal 01 which converts a reception signal fR1 of the first radio frequency band into the reception intermediate frequency signal fIFR, a second local oscillation signal 02 which converts a reception signal fR2 of the second radio frequency band into the reception intermediate frequency signal fIFR, a switch 04 which performs switching between first and second local oscillation signals to output them to a reception mixer 06, and a switch 05 which performs switching between the first or second local oscillation signal and a third local oscillation signal 03 are provided. The output of the switch 05 is inputted to the transmission mixer 07 and is multiplied by the transmission intermediate frequency signal fIFT to output a transmission signal fT1 having a prescribed frequency band of the first radio frequency band and a transmission signal fT2 having a prescribed frequency band of the second radio frequency band.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention assigns communication frequencies for transmission and reception of, for example, a digital car telephone system.
It can be commonly used in two bands such as the 00MHz band and the 1.5GHz band, and the two received signals of the predetermined high frequency bands of the 800MHz band and the 1.5GHz band are frequency-converted by the respective local oscillation frequency signals. The present invention relates to a configuration of a so-called heterodyne type dual band wireless communication device which outputs one common reception intermediate frequency signal or converts one common transmission intermediate frequency signal into two predetermined high frequency band transmission signals.
For this dual band wireless communication device, it is desired that the number of local oscillation circuits for heterodyne transmission / reception be as small as possible and the circuit scale of the entire device be small.

[0002]

2. Description of the Related Art In Japan, a digital car telephone service has been started in 1993. The radio frequency bands assigned to the communication frequencies of this car telephone service are the so-called 800 MHz band (810 to 956 MHz) and the 1.5 GHz band (1429 to 1501 MHz). 800MH on the other hand
Base station transmission frequency fT in the z band (810 to 956 MHz)
₁ is, for example, a predetermined lower band of 810 to 826 MHz (channel interval is 25 kHz, bandwidth ΔF1 is 16 MHz), the mobile station transmission frequency fT ₂ is its upper band 940 to 956 MHz (channel interval is 25 Bandwidth ΔF1 at 16MHz is the same at 16MHz). Since the base station and the mobile station face each other for receiving and transmitting communication,
The reception frequency fR ₁ of the base station is the upper band 940 to 956 MHz, _and the reception frequency fR ₂ of the mobile station is the lower band 810 to 826 MHz.
It becomes MHz, the frequency difference delta _TR of the transmission received at each station
In the 800MHz band, _ΔTR1 = _130MHz . Also, the other 1.
In the 5 GHz band (1429 to 1501 MHz), the base station transmission frequency fT
₂ is the specified upper band 1477 to 1501 MHz (channel spacing is 25 k
If the bandwidth ΔF2 is 24 MHz in Hz, the transmission frequency fT ₂ of the mobile station is 1429 to 1453 MHz in the lower band (the channel spacing is 25 k
In Hz, the bandwidth ΔF2 is the same at 24 MHz). Similarly, since the base station and the mobile station communicate with each other, the reception frequency fR ₁ of the base station is in the lower band 1429 to 1453MHz, _and the reception frequency fR ₂ of the mobile station is in the upper band 1477 to 1501MHz. the frequency difference delta _TR2 transmission reception of 1.5GHz band 48 MHz
Has become.

11 (a) and (b) of FIG. 10 are allocation diagrams of communication frequencies of each reception / transmission in the 800 MHz band and the 1.5 GHz band of the Japanese digital car telephone system of the above example.
In addition, the 800MH of the conventional digital mobile telephone system
An example of the configuration of a dual-band wireless communication device that can be used commonly in the z band and the 1.5 GHz band is shown below. The configuration example of the dual-band wireless communication device according to the related art of FIG. 11 is a base station or a mobile station, and the reception frequency fR is 8 in FIG.
There are two bands, 00MHz band and 1.5GHz band, of which 800MHz band
At (f ₁ ), the reception frequency fR ₁ is the predetermined lower band 810 to 826.
MHz (bandwidth ΔF1 is 16 MHz), the reception frequency fR _{2 in} the 1.5 GHz band (f ₂ ) is 1477 to 1501 MHz in the upper band (bandwidth ΔF2 = 24
MHz). The transmission frequency fT is the predetermined upper band 940 to 956 MHz (bandwidth ΔF1 = 16 MHz) in the 800 MHz band (fT ₁ ) and the lower band 1429 to 1453 MHz (bandwidth ΔF2 = 16 MHz) in the 1.5 GHz band (fT ₂ ). 24 MHz). In that case, the mixer (0
In 6), the received signals fR ₁ / fR _{2 in} the respective predetermined frequency bands of 800 MHz band and 1.5 GHz band, and the output f _LR1 (bandwidth ΔF1 = of the local oscillator circuit (01) for receiving 800 MHz band 16MHz) and 1.5
Output of local oscillator (02) for GHz band f _LR2 (bandwidth ΔF
2 = 24MHz) with _the switch (08), and they are multiplied by each other to convert the frequency respectively, and output intermediate frequency signal f _IFR1
And f _IFR2 are the same and common received intermediate frequency signal f _IFR
= 150 MHz. Further, in the transmitting side mixer (07), in order to obtain a transmission signal fT ₁ having a predetermined transmission / reception frequency difference Δ _TR1 = 130 MHz in the upper band of the 800 MHz band as its output,
Local oscillation circuit for transmission in the 800 MHz band with bandwidth ΔF1 = 16 MHz (0
The band for transmission in the 1.5 GHz band to obtain the transmission signal fT ₂ with the output f _{LT1 of} 3) and the specified transmission / reception frequency difference Δ _TR2 = 48 MHz in the lower band of the 1.5 GHz band and the bandwidth ΔF 2 = 24 MHz. Width ΔF2
= 24 MHz and an output f _LT2 of the local oscillation circuit _(04), the switch
(09) Switch to 800MHz band for multiplication with each other and 1.
Although one transmission intermediate frequency f _IFT common to the 5 GHz band was arbitrarily set, in the configuration example of FIG. 11, the one transmission intermediate frequency f _{IFT is set} to 170 MHz. In addition, although not shown, the reception intermediate frequency f _IFR and the transmission intermediate frequency f
_There has been a conventional example in which the _IFT and the 800 MHz band and the 1.5 GHz band have two separate frequencies.

[0004]

As described above, the conventional dual-band wireless communication device is provided with a local oscillator circuit for the receiving system,
As the local oscillation circuits for the transmission system, the reception local oscillation circuit (01), transmission local oscillation circuit (03) and 1.5
GHz local oscillator circuit (02), transmitter local oscillator circuit (0)
4) each has 2 systems, and a total of 4 local oscillator circuits (01)
Since the configuration has (4) to (04), there is a problem that the circuit scale of the entire wireless communication device becomes large.
An object of the present invention is a dual band radio in which each intermediate frequency for heterodyne reception and transmission of signals in two radio frequency bands is single, the number of local oscillation circuits is as small as possible, and the circuit scale of the entire device is small. It is to realize a communication device.

[0005]

To achieve the above object, the dual band radio communication apparatus according to claim 1 of the present invention has a basic configuration, referring to the principle configuration diagram of FIG. The received signal in the predetermined frequency band (fR ₁ ) of the
Input the received signal in the specified frequency band (fR ₂ ) of the radio frequency band of, and multiply each received signal (fR _1, fR ₂ ) by the receiving mixer (06).
And a local oscillation signal (f _LR1 , f _LR2 ) that is converted to an intermediate frequency signal (f _IFR1 , f _IFR2 ) with a constant frequency difference, outputs one common reception intermediate frequency signal (f _IFR ) 1
One transmission intermediate frequency signal (f _IFT ) is input, and at the transmission mixer (07) that multiplies with the transmission intermediate frequency signal (f _IFT ), the reception signal of each of the first and second radio frequency bands is Frequency (fR ₁ , fR ₂ )
And a transmission signal (fT ₁ ) of a predetermined frequency band of the first radio frequency band and a second radio frequency band, each having a constant frequency difference (Δ _TR1, Δ _TR2 ).
A dual-band wireless communication device for outputting a predetermined transmission signal in the frequency band (fT ₂₎ of (f _2), an intermediate frequency signal of the receive (f _IFR), the first or second radio frequency band A frequency equal to the transmission / reception frequency difference (Δ _TR1 or Δ _TR2 ),
The frequency (f _IFT ) of the intermediate frequency signal of the transmission is set to a frequency twice the transmission / reception frequency difference (2Δ _TR1 or 2Δ _TR2 ), and the received signal (fR ₁ ) of the first radio frequency band is set to the reception intermediate frequency. signal
a first local oscillation signal to convert to (f _IFR) (01), the second local oscillation signal to convert the received signal of the second radio frequency bands (fR ₂₎ on the received intermediate frequency signal (f _IFR) (02 ), A switch (04) for switching the first and second local oscillation signals (01) and (02) to output to the receiving mixer (06), and the first or second local oscillation signal and a constant frequency. A switch (05) for switching between the third local oscillation signal (03) of the difference is provided, and the output of the switch (05) is input to the transmission mixer (07) and multiplied by the transmission intermediate frequency signal (f _IFT ). , A transmission signal of a predetermined frequency band of the first radio frequency band (f
T ₁ ) and the transmission signal (f of the predetermined frequency band of the second radio frequency band (f
T ₂ ) and output.

[0006]

The dual band radio communication device according to claim 1 of the present invention.
In the setting, the first and second radio frequency bands by the reception mixer (06)
f_1,f₂Each received signal fR_1,fR₂After the frequency conversion of
Frequency f of the received intermediate frequency signal_IFRThe first radio frequency
Wave band f₁Transmission and reception frequency difference Δ_TR1Or the second radio frequency band f₂
Transmission and reception frequency difference Δ_TR2The frequency equal to
The first and second radio frequency band f by SA (07)_1,f₂Each transmission of
Force signal fT_1,fT₂One transmission intermediate frequency before frequency conversion to
Signal frequency f_IFTIs the transmission / reception frequency difference Δ_TR1Or Δ
_TR2Twice the frequency of 2Δ_TR1Or 2Δ_TR2To choose
Frequency of the received intermediate frequency signal f_IFRThe first
Line frequency band f₁Transmission and reception frequency difference Δ_TR1Frequency equal to
If, the received signal fR of the first radio frequency band₁The receiving intermediate
Frequency signal f_IFRReception of the first local oscillation signal (01)
Local oscillation signal f for signal_LR1Is f_LR1= fR₁− F_IFR= fR₁
−Δ_TR1= fR₁− (FT₁−fR₁) = 2 (fR₁−fT₁) ＋ fT₁= fT₁− 2
Δ_TR1= fT₁~ F_IFT= f_LT1Of the transmitted signal
Local oscillation signal f for _LT1It also becomes. Also, the reception intermediate frequency
Signal frequency f_IFRIs the second radio frequency band f₂Sending and receiving of
Wave number difference Δ_TR2If the frequency is equal to
Received signal fR in the frequency band₂The received intermediate frequency signal f_IFRStrange
The local oscillator signal for the received signal of the second local oscillator signal (02) to be converted
No. f_LR2 Is f_LR2= fR₂− F_IFR= fR₂−Δ_TR2= fR₂−
(fT₂−fR₂) = 2 (fR₂−fT₂) ＋ fT₂= fT₂−2Δ_TR2= fT₂−
 f_IFT= f_LT2The local oscillation signal for the transmission signal
It also becomes. Therefore, in the configuration of the present invention, it is necessary for reception and transmission.
The total number of local oscillation signals required is 3
Realizes a dual-band wireless communication device with a small configuration
Will be.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The principle diagram of the present invention shown in FIG.
In accordance with the embodiment of claim 1, the digital automobile radio system
 Dual-band wireless communication device for 800MHz band and 1.5GHz band
It is a block diagram of. Reception signal frequency at the input of the reception mixer (06)
The number fR is the first radio frequency band f₁= Reception of lower band of 800MHz band
Frequency fR₁= 810 to 826MHz (ΔF1 = 16MHz) and the second
Line frequency band f₂= Reception frequency fR of the upper band of 1.5 GHz band₂= 1477
~ 1501 MHz (ΔF2 = 24 MHz), which is
The frequency fT of the output transmission signal is the first radio frequency band f₁= 80
Transmission frequency fT of the upper band of 0MHz band₁= 940-956MHz (ΔF1
= 16 MHz) and the second radio frequency band f₂= Lower band of 1.5 GHz band
Transmission frequency fT₂= 1429 to 1453 MHz (ΔF2 = 24 MHz)
It And f₁= Transmission and reception frequency difference in 800MHz band is ΔTR₁= 130M
Hz and f₂= Transmission and reception frequency difference in 1.5 GHz band is ΔTR₂= 48 M
Hz. Reception intermediate frequency f of the output of the reception mixer (06)
_IFRIs the transmission / reception frequency difference ΔTR in the 800 MHz band, for example.₁= 130
If selected equal to MHz, transmit the input of the transmit mixer (07)
Intermediate frequency f_IFTIs 2ΔTR₁= 260MHz. There
F₂= Received signal fR in 1.5 GHz band₂First local oscillator signal for
Issue (01) f_LR2Is f_LR2= fR₂~ F_IFR= 1347 to 1371MHz
(ΔF2 = 24 MHz) and f₁= 800MHz band received signal fR₁for
Local oscillation signal fR_LR1And the transmitted signal fT₁Local oscillation signal for
fR_LT1The second local oscillation signal (02) shared by_LR1=
 fR_LT1= fR₁~ F_IFR= 680 to 696MHz (ΔF1 = 16MHz)
It And f₂= Transmit signal fT in 1.5 GHz band₂3rd department for
Local oscillation signal f of oscillation signal (03)_LT2Is f_{LT2 =} fT₂~ F
_IFT= fT₂ -2ΔTR₁= 1169 to 1193MHz (ΔF2 = 24MHz)
It Therefore, in the configuration of FIG.
The number of circuits is 3 (01) (02) (03)
Dual band of low configuration 800MHz band and 1.5GHz band
It becomes a wireless communication device. Also, although not shown in particular, during reception
Inter-frequency f_IFRIs the transmission / reception frequency difference ΔTR in the 1.5 GHz band.₂= 4
Even if 8MHz is selected, the previous 800MHz band transmission and reception
Frequency difference ΔTR₁= 130MHz, same as when you select
The total number of local oscillator circuits required is three.

FIG. 2 is a circuit diagram showing the local oscillation frequency more than the configuration of FIG.
The number of paths is reduced, and the number of paths is reduced to two.
An example is shown. In the configuration of FIG. 2, the dual band radio
In the communication device, the frequency f of the received intermediate frequency signal_IFR
Is the transmission / reception frequency of the first 800MHz band, as in the example of Fig. 1.
Difference Δ_TR1= 130MHz (or the second 1.5GHz radio frequency band)
Δ_TR2= 48MHz), but the middle frequency of transmission
Wave signal frequency f_IFTIs the transmission signal fT in the first radio frequency band
₁= 940 to 956MHz, the transmission / reception frequency of the first radio frequency band
Wave number difference Δ_TR1= The first frequency equal to 130MHz f_IFT1= Δ_TR1=
130 MHz, transmission signal fT in the second radio frequency band₂= 1429 ~ 14
For 53MHz, the first and second radio frequency bands
Difference in transmission and reception frequency of Δ_TR1~ Δ_TR2= 130−48 = 82
Second frequency f equal to MHz_IFT2= Δ_TR1~ Δ_TR2= 82 MH
z is the received signal fR in the first radio frequency band₁= 810 ~ 826M
Hz is the received intermediate frequency signal f_IFR= Δ_TR1= Change to 130MHz
F of the first local oscillation signal (01) for reception to be converted_LR1= 940 ~ 95
Received signal f of 6MHz (ΔF = 16MHz) and the second radio frequency band
R₂= 1477 to 1501MHz, the intermediate frequency signal f_IFR= 130MHz
Local signal for reception f to be converted to_LR2And at the same time the second
Frequency of the transmitted intermediate frequency signal f_IFT2= 82MHz, second radio
Frequency band transmission signal fT₂= Transmit from 1429 to 1453MHz
Local signal f_LT2F of the second local oscillation signal (02)_LR2=
f_LT2= 1347 to 1371 MHz (ΔF = 24 MHz) and the first and second
Switching the local oscillation signal (01) (02) to the reception mixer (06)
Output to the switch (04) and the first local oscillation signal f
_LR1And the transmission intermediate frequency signal f of the first frequency_IFT1Multiply by
Then, the transmitter signal f of the difference frequency _LT1= 810 to 826 MHz (3)
 And a mixer (09) for outputting the output (03) of the mixer (09)
Switching between the first (01) or second (02) local oscillation signal
Switch (05), and the output of the switch (05)
It is configured to input to the transmission mixer (07). This Figure 2
In this configuration, the number of mixers (09) is increased, but the number of local oscillator circuits
You only need two.

FIG. 3 shows an embodiment corresponding to claim 3 of the present invention.
2 which requires only two local oscillator circuits.
Shows another configuration example. In the configuration of FIG.
Frequency of the received intermediate frequency signal in the wireless communication device
 f_IFRIs the first radio frequency in the 800MHz band as in the example of Fig. 2.
Band transmission / reception frequency difference Δ_TR1= Frequency f equal to 130MHz
_IFRWhere f is the frequency of the transmitted intermediate frequency signal_IFTIs the
Transmission and reception frequency difference in one radio frequency band Δ_TR1= 130MHz and no second
Transmission and reception frequency difference in line frequency band Δ_TR2= Sum of 48MHz Δ _TR1 +
Δ_TR2= 130 + 48 = 178 MHz. And the transmission intermediate frequency
Signal f_IFT= 178MHz is the transmission signal fT of the first radio frequency band₁= 9
1st local oscillation signal for transmission to convert to 40-956MHz (01)
F_LT1= fT₁− F_IFT= 762 to 778MHz (ΔF = 16MHz)
And the transmitted intermediate frequency signal f_IFTTo the second radio frequency band
Signal fT₂= Second local oscillation signal converted to 1429 to 1453MHz
(02), f_LT2= f_LR2= 1607 to 1631MHz (ΔF = 24MHz)
Received signal fR₂Local oscillation signal f_LR2 Also shared.
Therefore, the first and second local oscillation signals (01) (02) are turned off.
Switch (05) that exchanges and outputs to the transmission mixer (07)
And f of the first local oscillation signal (01)_LT1And the transmission intermediate cycle
Wave signal f_IFT= 178 MHz Multiply with and sum frequency (03)
= 940 to 956 MHz received signal fR₁Local oscillation signal f_{LR 1}When
And the output (03) of the mixer (09)
The second local oscillation signal (02) = f_LR2= 1607 to 1631MHz
It has a switch (04) to change, the output of the switch (04)
f_LR1/ f_LR2Input to the receiving mixer (06)
I do. FIG. 4 shows the configuration of an embodiment corresponding to claim 4 of the present invention.
Therefore, the number of local oscillators is only 2
Another configuration example is shown. In the configuration of FIG. 4, the dual van
In the wireless communication device, the frequency f of the received intermediate frequency signal
_IFRIs the same as the example of Figs.
Radio frequency difference Δ in the radio frequency band_TR1= Equal to 130MHz
Frequency f_IFRWhere f is the frequency of the transmitted intermediate frequency signal
_IFTIs the transmission signal fT in the first radio frequency band₁= 940 ~ 956 MH
the first frequency f for z_IFT1Is the received intermediate frequency f_IFR
And the transmission / reception frequency difference in the first radio frequency band Δ_TR1 Difference with (f_IFR
−Δ_TR1) = 130-130 MHz = 0 direct current, 2nd radio frequency
Band transmission signal fT₂= 1429 to 1453 MHz 2nd frequency
 f_IFT2Is the received intermediate frequency f_IFRAnd transmission of the second radio frequency band
Reception frequency difference Δ_TR2Sum of (f_IFR+ Δ_TR2) = 130 +48 M
Set Hz = 178 MHz. And the transmission signal of the first radio frequency band
 fT₁= 940 to 956 MHz and received signal fR₁= 810-826MHz
The common first local oscillation signal (01) for_LR1= f
_LT1= 940-956 MHz (ΔF = 16 MHz), 2nd radio frequency band
Transmit signal fT₂= 1429 to 1453MHz and received signal fR₂= 1477
Shared second local oscillation signal for ~ 1501MHz (02)
F_LR2= F_LT2= 1347 to 1371 MHz (ΔF = 24 MHz)
It And the first local area that is shared for both reception and transmission
F of oscillation signal (01)_LR1= f_LT1 And the second local oscillation signal (02)
Of f_LR2= f_LT2And a switch (04) for switching between
The output of the switch (04) is sent to the receiving mixer (06) and the transmitting mixer.
It is configured to input to (07).

FIG. 5 shows the configuration of an embodiment corresponding to claim 5 of the present invention, showing another configuration example in which the number of local oscillation circuits is two. In the configuration of FIG. 5, in the dual band wireless communication device, the frequency f of the received intermediate frequency signal is
_IFR is the transmission / reception frequency difference in the first radio frequency band Δ _TR1 = 130MHz
And half of the sum of transmission / reception frequency difference Δ _TR2 = 48 MHz of the second radio frequency band [(Δ _TR1 + Δ _TR2 ) / 2] = (130 + 48) / 2 = 89 MHz,
The frequency f _IFT of the intermediate frequency signal for transmission is half the difference between the transmission / reception frequency difference Δ _TR1 in the first radio frequency band and the transmission / reception frequency difference Δ _{TR2 in} the second radio frequency band [(Δ _TR1 − Δ _TR2 ) / 2] = (130−48) /
2 = 41 MHz. The received signal f in the first radio frequency band f
R ₁ = 810 to 826 MHz is the received intermediate frequency signal f _IFR = 89 MHz
At the same time as conversion to the 41 MHz transmission intermediate frequency signal f
The first local oscillation signal (01) that converts the _IFT to the transmission signal fT ₁ = 940 to 956 MHz in the first radio frequency band is f _LR1 = f _LT1 = 899 to 915
MHz (ΔF = 16 MHz), the transmission signal fT of the second radio frequency band
₂ = 1429 to 1453MHz and the received signal fR ₂ = 1477 to 1501MHz, the common second local oscillation signal (02), f _LR2 = f
_LT2 = 1388 to 1412MHz (ΔF = 24MHz). And the first
And a switch for switching the second local oscillation signal (01) (02)
The output of (04) is output to the reception mixer (06) and the transmission mixer (07).

FIG. 6 shows an embodiment corresponding to claim 6 of the present invention.
Another configuration in which the number of local oscillation circuits is 2
An example is shown. In the configuration of FIG. 6, the dual band radio
In the communication device, the frequency f of the received intermediate frequency signal_IFR
Is the transmission and reception frequency difference Δ in the first radio frequency band in the 800MHz band.
_TR1= Frequency f equal to 130MHz_IFRHowever, the transmission middle
Frequency f of the frequency signal_IFTIs the transmission signal of the first radio frequency band
 fT₁= 1st frequency f for 940 to 956 MHz_IFT1Is
Signal intermediate frequency f_IFRAnd the transmission / reception frequency difference between the first radio frequency band
Δ_TR1 Sum of (f_IFR+ Δ_TR1) = 130 +130 MHz = 260 MHz
And the transmission signal fT of the second radio frequency band₂= 1429 to 1453 MHz
Second frequency f for_IFT2Is the received intermediate frequency f_IFRWhen
Transmission and reception frequency difference in the second radio frequency band Δ_TR2Sum of (f_IFR+
Δ_TR2) = 130 + 48 MHz = 178 MHz. And the first radio
Frequency band transmission signal fT₁= 940 to 956MHz and received signal fR₁=
 Shared first local oscillation signal for 810 to 826 MHz
F for (01)_LR1= f_LT1= 680 to 696 MHz (ΔF = 16 MHz),
Transmission signal fT of the second radio frequency band ₂= 1429 to 1453MHz and received signal
Issue fR₂= 1477 〜 1501MHz common second local departure
Swing signal (02) is f_LR2= f_LT2= 1607 to 1631MHz (ΔF = 24MH
z). And the first shared for receiving and transmitting
Local oscillation signal of (01) f_LR1= f_LT1 And the second local oscillator signal
Issue (02) f_LR2= f_LT2 Equipped with a switch (04) for switching
The output of the switch (04) is transmitted to the receiving mixer (06) and the transmitting mixer.
It is configured to input to (07).

FIG. 7 is a configuration diagram of an embodiment corresponding to claim 7 of the present invention, showing another configuration example in which the number of local oscillation circuits is two. In the configuration of FIG. 7, in the dual band wireless communication device, the frequency f of the received intermediate frequency signal is
_IFR is the frequency f _IFR equal to the transmission / reception frequency difference _ΔTR1 = 130MHz of the first radio frequency band of 800MHz band, but the frequency f _IFT of the transmission intermediate frequency signal is the transmission signal fT ₁ of the first radio frequency band fT ₁ = The first frequency f _IFT1 for 940 to 956 MHz is
Reception intermediate frequency f _IFR and the sum of the transmission and reception frequency difference delta _TR1 of the first radio frequency band _{(f IFR + Δ TR1) =} 130 +130 MHz = 260 M
Hz, transmission signal in the second radio frequency band fT ₂ = 1429 to 1453 M
Intermediate frequency f for Hz f Second frequency of _IFT f
_IFT2 is a difference _{(f IFR -Δ TR1) = 130-130} = 0 and the reception intermediate frequency f _IFR and reception frequency difference delta _TR1 of the first radio frequency band,
The first frequency is f _IFT2-1 and the difference between the transmission and reception frequency difference Δ _{TR2 in} the second radio frequency band (f _IFR −Δ _TR2 ) = 130−48 MHz =
82 MHz is the second frequency f _IFT2-2 . And the first
Radio frequency band transmit signal fT ₁ = 940 to 956MHz and receive signal f
The common first local oscillation signal (01) for R ₁ = 810 to 826 MHz is f _LR1 = 680 to 696 MHz (ΔF = 16 MHz),
The second local oscillation signal (02) for the second radio frequency band transmission signal fT ₂ = 1429 to 1453MHz and the reception signal fR ₂ = 1477 to 1501MHz is shared by f _LR2 = 1607 to 1631MHz (ΔF = 24MHz).
And Then, f _{LR1 of} the first local oscillation signal (01) and the second local oscillation signal (02) which are shared for reception and transmission
A switch (04) for switching between f _LR2 and
The output of (04) is sent to the reception mixer (06) and the transmission signal of the first intermediate frequency signal f _IFT in the first radio frequency band fT ₁ = 940 to 956 M
Input to the mixer (07) for multiplying the first frequency f _IFT1 = 260MHz for Hz, the output of the mixer (07), the first frequency f of the second frequency f _{I FT2} transmission intermediate frequency f _IFT
Input to the transmission mixer (13) for multiplication with _IFT2-1 = 0 or the second frequency f _IFT2-2 = 82MHz, and as the output of the transmission mixer (13), the transmission signal fT ₁ = 940 ~ of the first radio frequency band It is configured to output a transmission signal fT ₂ = 1429 to 1453 MHz of 956 MHz or the second radio frequency band.

FIG. 8 shows an embodiment corresponding to claim 8 of the present invention.
2 is a block diagram of the configuration of FIG.
One is a synthesizer type that outputs multiple frequencies.
However, the other one is an oscillator that outputs a single frequency.
Then, a simpler configuration example is shown. In the configuration of FIG.
In the dual band wireless communication device, the reception intermediate frequency signal
Signal frequency f_IFRIs transmitted in the first 800 MHz band radio frequency band.
Reception frequency difference Δ_TR1= Frequency f equal to 130MHz_IFRTosu
Frequency of the transmitted intermediate frequency signal f_IFTIs the receiving intermediate
Frequency f_IFRAnd the second 1.5 GHz band radio frequency band
Wave number difference Δ_TR2= Sum of 48MHz (f_IFR+ Δ_TR2) = 130 + 48
= 178 MHz. And the transmitted intermediate frequency signal f_IFT= 17
Transmit signal fT of 8 MHz and the first radio frequency band₁= 940-956 MH
Frequency difference (fT = 16MHz) (fT₁-F_IFT) Equal to
Local oscillation signal f for transmission in one radio frequency band_LT1= 762 ~ 778MH
Second radio that includes z band (ΔF1 = 16MHz) and is wider than that
For example, f of the local oscillation signal for transmission in the frequency band_LT2= 760 ~ 784M
The first local oscillation signal (01) having the Hz band (ΔF2 = 24MHz)
And the frequency sum (03) of the first local oscillation signal (01) is
Received signal fR in the radio frequency band (ΔF2)₂= 1477 to 1501
MHz and the reception intermediate frequency f_IFR= Receive different by 130 MHz
Local oscillation frequency f for_LR2= fR₂ + F_IFR= 1607 〜 1631MH
At the same time as z (ΔF2 = 24MHz), transmission of the second radio frequency band
Signal fT₂= 1429 to 1453MHz (ΔF2 = 24MHz) and the transmission intermediate frequency
Wave number f_IFT= 178MHz different local oscillation frequency for transmission f
_LT2= fT₂+ F_IFT= 1607 to 1631MHz (ΔF2 = 24MHz)
The second local oscillation signal (02) with a single frequency A = 847MHz,
Multiplying the first and second local oscillation signals (01), (02),
Sum frequency (03) = f_LR2= f_LT2= 1607 to 1631MHz (ΔF2 = 24MHz)
A first mixer (09) for outputting the first local oscillation signal (01)
= 760 to 784MHz (ΔF2 = 24MHz) in the first radio frequency band
Credit local oscillation signal f_LT1= 762 to 778MHz band (ΔF1 = 16M
Hz) and the transmitted intermediate frequency signal f_IFT= 178MHz
And sum frequency (08) = (f_LT1+ F_IFT) The first radio frequency
Local oscillation signal f for band reception_LR1= 940-956MHz (ΔF1 = 1
Second mixer (14) for outputting 6 MHz) and the second mixer (14)
Output of (08) f _LR1 And f of the output (03) of the first mixer (09)
_LR2Output f of switch (04) that switches between and _LR1/ f_LR2To
Input to the reception mixer (06). Also, the first local oscillation
Local oscillation signal f for transmission in the first radio frequency band in the signal (01)
_LT1= 762 to 778 MHz (ΔF1) and the output of the first mixer (09) (0
3) = f_LT2Switch to switch between = 1607 to 1631MHz (ΔF2)
Output f of (05)_LT1/ f_LT2To the transmission mixer (07).
Is configured. According to the embodiment of claim 8,
For example, as a frequency conversion mixer, the first mixer (09) and the second mixer (09)
A mixer (14) is added, but the number of local oscillator circuits is 2
Only one (01) (02) and one (01) has multiple frequencies 760
It is a synthesizer type that outputs ~ 784MHz, but another one
(02) is an oscillator that outputs a single frequency of 847 MHz.
The dual-band wireless communication device has a simple structure.

Another configuration for simplifying the dual band radio communication device will be described with reference to FIG. In FIG. 9 (a), (15) is a filter BPF that selectively passes only the first local oscillation frequency signal (1), and (16) only the second local oscillation frequency signal (2). Filter BPF that selectively passes
Is. Since the local oscillation frequency signals (1) and (2) pass through the filters BPF (15) and (16) and are input to a mixer (not shown), the required local oscillation frequency signal (1) or
By operating only (2), the switch (04) of FIGS. 1 to 8 for switching the local oscillation frequency signals (1) and (2) can be eliminated.

In FIG. 9 (b), (17) is an isolator for selectively passing only the first local oscillation frequency signal (1), and (18) is the second local oscillation frequency signal (2). It is an isolator that selectively passes only. Each isolator
(17) Through (18), each local oscillation frequency signal (1) (2)
Is input to a mixer (not shown), the local oscillation frequency signal (1) or (2) is switched by operating only the required local oscillation frequency signal (1) or (2). (04)
Can be deleted.

[0016]

As described above, according to the present invention, a local oscillation signal for reception which converts two high frequency reception signals of the first and second radio frequency bands into a single intermediate frequency signal,
Since the total number of local oscillation signals for transmission that converts another single intermediate frequency transmission signal into two high frequency transmission signals can be made smaller than before, it is possible to reduce the total number of local oscillation signals to 800 MHz and 1.5 MHz for digital car telephone systems. It is possible to economically configure a dual band wireless communication device commonly used in the GHz band and the like.

[Brief description of drawings]

FIG. 1 is a principle diagram showing a basic configuration of a dual-band wireless communication device of the present invention.

FIG. 2 is a configuration diagram of a dual-band wireless communication device of an embodiment corresponding to claim 2 of the present invention.

FIG. 3 is a configuration diagram of a dual-band wireless communication device of an embodiment corresponding to claim 3 of the present invention.

FIG. 4 is a configuration diagram of a dual-band wireless communication device of an embodiment corresponding to claim 4 of the present invention.

FIG. 5 is a configuration diagram of a dual-band wireless communication device of an embodiment corresponding to claim 5 of the present invention.

FIG. 6 is a configuration diagram of a dual-band wireless communication device of an embodiment corresponding to claim 6 of the present invention.

FIG. 7 is a configuration diagram of a dual band wireless communication device of an embodiment corresponding to claim 7 of the present invention.

FIG. 8 is a configuration diagram of a dual-band wireless communication device of an embodiment corresponding to claim 8 of the present invention.

FIG. 9 is an explanatory diagram of another configuration of the dual band wireless communication device according to the embodiment of the present invention.

[Figure 10] 800 MHz band and 1.5 GHz of car telephone system
Band frequency allocation diagram

FIG. 11 is a diagram showing a configuration example of a dual-band wireless communication device according to a conventional technique

[Explanation of symbols]

(01) to (03) are local oscillator circuits, (04) and (05) are switches, (06)
Is a reception mixer, (07) is a transmission mixer, (08) is a transmission intermediate frequency circuit, fR ₁ and fR ₂ are reception signal frequencies in the first and second radio frequency bands, and fT ₁ and fT ₂ are first and _second reception signal frequencies. Each transmission signal frequency in the second radio frequency band, f _IFR is a reception intermediate frequency signal, and Δ _TR is a transmission / reception frequency difference.

Front page continuation (72) Inventor Hiroyasu Nakagawa 1-2-25, Ichibancho, Aoba-ku, Sendai City, Miyagi Prefecture Fujitsu Tohoku Digital Technology Co., Ltd. (72) Inventor Katsunori Hayasaka Ichibancho, Aoba-ku, Sendai City, Miyagi Prefecture 1-225 Fujitsu Tohoku Digital Technology Co., Ltd. (72) Inventor Osamu Kuroda 1-2-25 Ichibancho, Aoba-ku, Sendai City, Miyagi Prefecture Fujitsu Tohoku Digital Technology Co., Ltd. (72) Inventor Sakata Minoru 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Within Fujitsu Limited (72) Inventor Koji Chiba 2-10-1 Toranomon, Minato-ku, Tokyo NTT Mobile Communications Network Inc. (72) Inventor Takeda Souji 2-10-1 Toranomon, Minato-ku, Tokyo NTT Mobile Communications Network Co., Ltd.

Claims (8)

[Claims] 1. A predetermined frequency band of the first radio frequency band (f
The reception signal of R ₁ ) and the reception signal of a predetermined frequency band (fR ₂ ) of the second radio frequency band different from that are input, and the reception mixer (06)
Local oscillation signal (f _LR1 , _{fR1 ,} fR ₂ ) which is multiplied by to be converted into intermediate frequency signals (f _IFR1 , f _IFR2 ) with constant frequency difference
f _LR2 ) outputs one common reception intermediate frequency signal (f _IFR ) and one separately determined transmission intermediate frequency signal
(f _IFT ) is input, and at the transmission mixer (07) that multiplies with the transmission intermediate frequency signal, the reception signals (fR ₁ , fR ₂ ) of the first and second radio frequency bands are kept constant. Frequency difference (Δ
_TR1, Δ _TR2 ) dual band that outputs a transmission signal (fT ₁ ) of a predetermined frequency band of the first radio frequency band and a transmission signal (fT ₂ ) of a predetermined frequency band of the second radio frequency band In the wireless communication device, the received intermediate frequency signal (f _IFR )
Or, the difference between the transmission and reception frequency of the second radio frequency band (Δ _TR1 or Δ
_TR2 ), and the frequency (f _IFT ) of the intermediate frequency signal of the transmission is twice the frequency (2Δ) of the transmission / reception frequency difference.
_TR1 or 2Δ _TR2 ) as the received signal in the first radio frequency band
A first local oscillation signal (01) for converting (fR ₁ ) into the reception intermediate frequency signal (f _IFR ) and a first local oscillation signal (fR ₂ ) for converting the reception signal (fR ₂ ) in the second radio frequency band into the reception intermediate frequency signal. 2 local oscillation signal (02)
A switch (04) for switching between the first and second local oscillation signals (01) and (02) and outputting to the reception mixer (06), and the first or second local oscillation signal and the third local oscillation signal. A switch (05) for switching between the local oscillation signal (03) and the output of the switch (05) is input to the transmission mixer (07) to transmit the transmission intermediate frequency signal (f
_IFT ) to output a transmission signal (fT ₁ ) in a predetermined frequency band of the first radio frequency band and a transmission signal (fT ₂ ) in a predetermined frequency band of the second radio frequency band. A unique dual-band wireless communication device. 2. The dual-band wireless communication device, wherein the frequency (f _IFR ) of the intermediate frequency signal for reception is equal to the transmission / reception frequency difference (Δ _TR1 or Δ _TR2 ) of the first or second wireless frequency band. , The frequency of the transmitted intermediate frequency signal (f _IFT )
Is the first frequency equal to the transmission / reception frequency difference (Δ _TR1 ) of the radio frequency band for the transmission signal (fT ₁ ) of the first radio frequency band.
(f _IFT1 ), and for the transmission signal (f _{T 2} ) in the second radio frequency band, the second equal to the difference (Δ _{TR1 to} Δ _TR2 ) in the transmission and reception frequency difference between the first and second radio frequency bands. A first local oscillation signal (01) for converting the reception signal (fR ₁ ) in the first radio frequency band into the reception intermediate frequency signal (f _IFR ) as the frequency (f _IFT2 );
To the reception mixer (06) by switching between the second local oscillation signal (02) for converting the reception signal (fR ₂ ) in the radio frequency band into the reception intermediate frequency signal and the first and second local oscillation signals. The switch (04) for outputting, the first local oscillation signal (f _LR1 ) and the first local oscillation signal (f _LR1 )
Multiply the transmitted intermediate frequency signal (f _IFT1 ) with the difference frequency (0
And a switch (05) for switching between the output (03) of the mixer (09) and the first (01) or second (02) local oscillation signal. 2. The dual band wireless communication device according to claim 1, wherein the output of the switch (05) is input to the transmission mixer (07). 3. The dual-band wireless communication device, wherein the frequency (f _IFR ) of the received intermediate frequency signal is set to the first or second
The frequency (f _IFT ) of the transmission intermediate frequency signal is set to the frequency equal to the transmission / reception frequency difference (Δ _TR1 or Δ _TR2 ) in the radio frequency band
The transmission intermediate frequency signal (f _IFT ) is set as a frequency equal to the sum (Δ _TR1 + Δ _TR2 ) of the transmission and reception frequency differences between the first and second radio frequency bands and the transmission frequency signal (f T ₁ )
A first local oscillation signal (01) for converting into a first local oscillation signal (01), a second local oscillation signal (02) for converting the transmission intermediate frequency signal (f _IFT ) into a transmission signal (fT ₂ ) in a second radio frequency band, A switch (05) for switching the first and second local oscillation signals (01) and (02) to output to the transmission mixer (07), and the first (01) or second (02) local oscillation signal (f _LT1 or f _LT2 ) and the transmission intermediate frequency signal (f _IFT ) are multiplied to output a sum or difference frequency (03) (09)
And a switch (04) for switching the output (03) of the mixer (09) and the first or second local oscillation signal, and the output of the switch (04) is input to the reception mixer (06). The dual band wireless communication device according to claim 1, wherein 4. In the dual-band wireless communication device, the frequency (f _IFR ) of the intermediate frequency signal for reception is set to a frequency equal to the transmission / reception frequency difference (Δ _TR1 ) in the first radio frequency band, and the intermediate frequency signal for transmission is frequency (f _IFT), for the transmission signal of the first radio frequency band (fT ₁₎ the received intermediate frequency (f
_IFR ) and the transmission / reception frequency difference ( _ΔTR1 ) (f _IFR −
Zero frequency transmission intermediate frequency signal of the Δ _TR1) (f _IFT1) and then, the transmission signal of the second radio frequency band (the reception intermediate frequency (f _IFR) and said transmission reception frequency difference for fT ₂₎ (delta _TR2) Sum of (f _IFR
As a transmission intermediate frequency signal (f _IFT2 ) having a frequency equal to + Δ _TR2 ), the reception signal (fR ₁ ) in the first radio frequency band is converted into the reception intermediate frequency signal (f _IFR ) and at the same time, the transmission intermediate frequency signal of the zero frequency. The signal (f _IFT1 ) is the transmission signal (f
The first local oscillation signal (01) to be converted into T ₁ ) and the reception signal (fR ₂ ) in the second radio frequency band are converted into the reception intermediate frequency signal (f _IFR ), and at the same time, the transmission intermediate frequency signal (f _IFT2) ) Is converted into a transmission signal (fT ₂ ) in the second radio frequency band, the second local oscillation signal (0
2) and a switch (04) for switching the first and second local oscillation signals (01) (02) and outputting to the reception mixer (06) and the transmission mixer (07). The dual-band wireless communication device according to claim 1. 5. In the dual-band wireless communication device, the frequency (f _IFR ) of a received intermediate frequency signal is set to a transmission / reception frequency difference (Δ _TR1 ) in a first radio frequency band and a transmission / reception frequency difference (Δ _TR1 ) in a second radio frequency band. Half of the sum of Δ _TR2 ) [(Δ _TR1 + Δ _TR2 ) / 2]
And the frequency (f _IFT ) of the intermediate frequency signal for transmission is half the difference between the transmission / reception frequency difference (Δ _TR1 ) of the first radio frequency band and the transmission / reception frequency difference (Δ _TR2 ) of the second radio frequency band [(Δ _TR1 −Δ _TR2 ) /
2], the reception signal (fR ₁ ) in the first radio frequency band is converted into the reception intermediate frequency signal (f _IFR ), and at the same time, the transmission intermediate frequency signal (f _IFT1 ) having the frequency is transmitted in the first radio frequency band.
The first local oscillation signal (01) to be converted into (fT ₁ ) and the reception signal (fR ₂ ) in the second radio frequency band are converted into the reception intermediate frequency signal (f _IFR ) and at the same time the transmission intermediate frequency signal (f _IFT2 ) second
The second local oscillation signal (02) to be converted into the transmission signal (fT ₂ ) in the radio frequency band and the first and second local oscillation signals (01) (02) are switched to transmit to the reception mixer (06) A switch (04) for outputting to a mixer (07) is provided.
The described dual band wireless communication device. 6. In the dual band wireless communication device, the frequency (f _IFR ) of the reception intermediate frequency signal is set to a frequency equal to the transmission / reception frequency difference (Δ _TR1 ) in the first radio frequency band, and the transmission intermediate frequency signal. The frequency (f _IFT ) of
For the transmission signal (f T ₁ ) in the radio frequency band, the sum (f _IFR + Δ) of the reception intermediate frequency (f _IFR ) and the transmission and reception frequency difference (Δ _TR1 ).
A first frequency transmission intermediate frequency signal of _TR1) (f _IFT1), the received intermediate frequency (f _IFR) and said transmission reception frequency difference with respect to the transmission signal of the second radio frequency band (fT ₂₎ (Δ _TR2) Sum of (f _IFR
+ Δ _TR2 ) As a transmission intermediate frequency signal (f _IFT2 ) of the second frequency, the reception signal (fR ₁ ) of the first radio frequency band is converted into the reception intermediate frequency signal (f _IFR ) and at the same time the transmission of the first frequency is performed. Intermediate frequency signal (f _IFT1 ) is transmitted signal in the first radio frequency band (f _{T 1} )
The first local oscillation signal (01) and the reception signal (fR ₂ ) in the second radio frequency band are converted into the reception intermediate frequency signal (f _IFR ) and at the same time the transmission intermediate frequency signal (f the _IFT2) transmission signals of the second radio frequency band (a second local oscillation signal to convert to fT ₂₎ (02), said first and second local oscillation signal (01) (02)
A switch (04) for outputting the F received mixer and (06) the transmission mixer and (07) by switching, first frequency transmission intermediate frequency signal (f _IFT1) and the second frequency transmission intermediate frequency signal (f _IFT2 )
Switch to switch between and to output to the transmission mixer (07)
The dual band wireless communication device according to claim 1, further comprising (12). 7. The dual-band wireless communication device, wherein the frequency (f _IFR ) of the intermediate frequency signal for reception is equal to the transmission / reception frequency difference (Δ _TR1 ) in the first radio frequency band, and the frequency of the intermediate frequency signal for transmission. 1st frequency of (f _IFT ) (f
_IFT1 ) is the _sum of the reception intermediate frequency (f _IFR ) and the transmission / reception frequency difference (Δ _TR1 ) in the first radio frequency band (f _IFR +
Δ _TR1 ) and the second frequency (f _IFT2 ) of the transmission intermediate frequency signal
Is the difference (f _IFR −Δ _TR1 ) between the reception intermediate frequency (f _IFR ) and the transmission and reception frequency difference (Δ _TR1 ) of the first radio frequency band for the transmission signal (f T ₁ ). ) Of the zero-frequency transmission intermediate frequency signal (f _IFT2-1 ), and the transmission signal of the second radio frequency band (f
For T ₂ ), the difference frequency (f _IFR −) between the reception intermediate frequency (f _IFR ) and the transmission and reception frequency difference in the second radio frequency band (Δ _TR2 ).
As a transmission intermediate frequency signal (f _IFT2-2 ) of Δ _TR2 ), a first local oscillation signal (01) for converting the reception signal (fR ₁ ) of the first radio frequency band into the reception intermediate frequency signal (f _IFR ) , A second local oscillation signal (02) for converting the reception signal (fR ₂ ) in the second radio frequency band into the reception intermediate frequency signal (f _IFR ), and the first and second local oscillation signals
The output of the switch (04) for switching between (01) and (02) is fed to the reception mixer (06) and the signal of the first frequency of the transmission intermediate frequency (f _IFT1 ).
And the output of the mixer (07) is input to the transmission mixer (13) that multiplies with the signal (f _IFT2 ) of the second frequency of the transmission intermediate frequency, Transmission mixer (13)
A transmission signal (fT ₁ ) in a predetermined frequency band of the first radio frequency band and a transmission signal (fT ₂ ) in a predetermined frequency band of the second radio frequency band are output as Item 2. A dual-band wireless communication device according to item 1. 8. The dual-band wireless communication device, wherein the frequency (f _IFR ) of the reception intermediate frequency signal is set to a frequency equal to the transmission / reception frequency difference (Δ _TR1 ) of the first radio frequency band, and the frequency (f _IFR ) of the transmission intermediate frequency signal (f _IFT ), the received intermediate frequency (f _IFR )
And the transmission / reception frequency difference (Δ _TR2 ) of the second radio frequency band as a frequency (f _IFR + Δ _TR2 ) of the transmission intermediate frequency signal (f
_From the band (ΔF1) of the local oscillation signal for transmission (f _LT1 ) in the first radio frequency band, which is equal to the frequency (fT ₁ −f _IFT ) of the difference between the _IFT ) and the transmission signal in the first radio frequency band (fT ₁ ). The frequency difference (03) between the first local oscillation signal (01) and the first local oscillation signal (01) having the band (ΔF2) of the transmission local oscillation signal (f _LT2 ) in the second wide radio frequency band Is a local oscillation frequency for reception (f _LR2 ) that differs from the received signal (f R ₂ ) in the second radio frequency band (ΔF ₂ ) by the received intermediate frequency (f _IFR ), and at the same time the transmission of the second radio frequency band A single frequency (A) that results in a local oscillation frequency for transmission (f _LT2 ) that differs from the signal (f T ₂ ) by the transmission intermediate frequency (f _IFT ).
A second mixer (09) for multiplying the first local oscillation signal (02) by the second local oscillation signal (02) and outputting the sum frequency (03); The frequency sum is obtained by multiplying the band (ΔF1) of the transmission local oscillation signal (f _LT1 ) of the first radio frequency band in the first local oscillation signal (01) by the transmission intermediate frequency signal (f _IFT ). (0
8) A second mixer (14) that outputs a local oscillation signal (f _LR1 ) for reception in the first radio frequency band, an output (08) of the second mixer (14) and an output of the first mixer (09) Switch (04) to switch between (03) and
Is input to the reception mixer (06), and a local oscillation signal for transmission (f) in the first radio frequency band in the first local oscillation signal (01) is input.
The output of the switch (05) for switching the band (ΔF1) of _LT1 ) and the output (03) of the first mixer (09) is used as the transmission mixer (07).
The dual-band wireless communication device according to claim 1, wherein